Bird species populations collapsing catastrophically
The media spokesperson for the Swiss Ornithological Institute cites intensive agriculture as the main cause of this development — a practice that has now spread to mountainous regions as well, putting breeding bird populations there under increasing pressure.
According to a study, the population of breeding birds in agricultural areas across Europe has declined by more than half over the past few decades.
Since 1980, the population of farmland birds in the EU has collapsed by around 56 percent. Affected species include the skylark, the common starling, and the lapwing, among others. This emerges from data compiled by the European Bird Census Council, a network of European ornithological experts based in Nijmegen, the Netherlands.
Switzerland is unfortunately no exception to this alarming trend, as Livio Rey of the Swiss Ornithological Institute in Sempach confirms. Since the 1990s, the populations of 29 typical farmland bird species in this country have more than halved.The populations of formerly common species have collapsed catastrophically over the past 25 years, according to Rey: whinchat numbers have dropped by 60 percent, skylarks by 50 percent, and red-backed shrikes by 40 percent.
Less food and fewer nesting sites
Pesticides and over-fertilisation are causing the disappearance of insects, which form the most important food source for many bird species.
«Intensive fertilisation causes grass to grow more densely, making it impossible for birds to reach the ground to forage or build nests», says Rey. In addition, accelerated grass growth leads to earlier and more frequent mowing. «Ground-nesting species no longer have enough time to raise their young before the nest is destroyed again by the next mowing.»
Environmental targets not being met
Rey cites as a further reason the fact that biodiversity promotion areas make up too small a proportion of agricultural land and are of too low a quality. A recent study by the University of Bern and the Bern University of Applied Sciences reached the same conclusion. «For breeding birds, diverse support areas are important — ones where not everything is cut to the same length and where trees, hedges, and other small structures offer nesting sites and foraging space», says the media spokesperson of the Bird Observatory.
The Federal Council also noted in a 2016 report that none of the environmental goals for agriculture agreed upon in the 1990s had been fully achieved. As a result, around two-thirds of the originally targeted 65’000 hectares of high-quality habitat for breeding birds in the Mittelland are still missing, as documented in the 2013–2016 Breeding Bird Atlas published by the Swiss Ornithological Institute in Sempach.
This negative trend must be urgently corrected in the future direction of agricultural policy, so that we can paint a more positive picture for breeding birds in cultivated land.
Livio Rey of the Swiss Ornithological Institute in Sempach
